Samsung S3C2451X User Manual page 524

HSMMC CONTROLLER
Auto CMD12 CRC
The relation between Command CRC Error and Command Timeout Error
The timing of changing Auto CMD12 Error Status can be classified in three scenarios:
(1) When the Host Controller is going to issue Auto CMD12
Set D00 to 1 if Auto CMD12 cannot be issued due to an error in the previous command.
Set D00 to 0 if Auto CMD12 is issued.
(2) At the end bit of an Auto CMD12 response
Check received responses by checking the error bits D01, D02, D03 and D04.
Set to 1 if error is detected.
Set to 0 if error is not detected.
(3) Before reading the Auto CMD12 Error Status bit D07
Set D07 to 1 if there is a command cannot be issued
Set D07 to 0 if there is no command to issue
Timing of generating the Auto CMD12 Error and writing to the Command register are asynchronous. Then
D07 shall be sampled when driver never writing to the Command register. So just before reading the Auto
CMD12 Error Status register is good timing to set the D07 status bit. An Auto CMD12 Error Interrupt is
generated when one of the error bits D00 to D04 is set to 1. The Command Not Issued By Auto CMD12
Error does not generate an interrupt.
Preliminary product information describe products that are in development,
for which full characterization data and associated errata are not yet available.
21-56
Specifications and information herein are subject to change without notice.
Auto CMD12
Error Timeout Error
0
0
1
1
Kinds of error
0 No Error
1 Response Timeout Error
Response CRC Error
0
1 CMD line conflict
S3C2451X RISC MICROPROCESSOR